guide to royal marriages, personal unions and claim throne.

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In some (rare) cases a vassal with your dynasty will be inherent at their monarch death. How does this works?

the following might still have errors, as its really opaque.

same mechanic as inheriting random nations.

you can even inherit vassals of someone *else* this way.

it has nothing to do with PU, but rather is depending on the tier system en the roll a monarch makes when he takes the throne.

if then the nation is heirless and in right tier in a certain period of 5 years, it could trigger.

details are in the guide, under inheritance section.

1. So HOW does it work exactly (this is theory):

I wish to thank @Ternega to submit this theory in the thread. What follows is his theory on how inheritance works, and it is backed by observations and indirect evidence.

I will refer to a potential inheritor (player or random) as country X, to their existing PUs as PUs and to countries with disputed succession as DS.

You will need knowledge in chapter 4 to understand what is written below, as it involves tiers of nations.

Inheritance consists of 3 steps:

A) Random dice roll for all nations, the INHERITANCE ROLL (IR for short) for nation X

IR is not displayed anywhere in the interface and cannot be influenced by reloading game. Its up for debate when this roll occurs, but indirect evidence and observations leads to conclusion that it is likely rolled when any monarch takes throne in any nation, OR in periodic intervals of few decades. What is certain and backed by numerous observers: save scumming with an old ruler will NOT alter the outcome of inheritance, which leads to the above conclusion it has to happen lot sooner. Inheriting independent nations is special case, see below.

My own theory is that the actual chance for PU (or random inheritance) is calculated when the new (current) ruler takes/took the throne, and NOT when the current ruler dies. After that, this chance gets re-rolled on periodic (long intervals; length of timer unknown but likely 10+ years). Save scumming with a 70+ old king and hoping you will inherit won't work, as the chance is already calculated when he took throne or the SAME for a long period. I think they installed this to avoid players save scumming till they inherit.

Proof enough if you ask me ;)

This roll will be checked if ANY heirless nation or PU subject can be directly inherited.

B) Comparing IR to the individual inheritance threshold chance (IT for short)

this is the % chance you can see in tooltips of PU subjects) of each PU stable for 50 years and for any DS nations that you can legally inherit (heirless (vassal) nations being in inheritance tier).

The full probability to inherit -for PU overlord or strongest successor for inheritance tier heirless (vassal) nations- can be calculated as 5 x Diplomatic Reputation for + Stability (Senior) + 5 if both partners share a culture group -1 per province in the junior partner or inheritance tier heirless nation.

I bet you say "wait what" now :rolleyes:


The rule of thumb is you can start to get % chance to inherit a junior PU or random nation that has dip rep times 5 in amount of provinces. You will get chance even sooner if you share culture, and a bit more if you got +3 stab.

important sidenote: Take into account that stacking these modifiers doesn't mean a guaranteed inheritance; the roll the game does on monarch taking throne has to be good enough. The modifers above just widen the range in which the inheritance roll is successful (which is something that is not very Obvious).



example: Austria has 10 diplo rep, 3 stability. Same culture group 3 province nation is heirless and in inheritance tier and their ruler dies , or Austria 3 province PU subject has been subject for 50+ years and new ruler takes throne in Austria.
Austria would get 50% chance from dip rep, 3% from stability, 5% from same culture group and -3% from 3 provinces in PU/DS for a total of 55% as inheritance treshold chance.

the inheritance chance of PU subject is calculated with diplomatic Reputation, which is 5% per point, and number of provinces owned by the junior, which is -1% per province. Austria would get 70% chance to inherit at 14 dip rep, before counting provinces of junior PU or DS.

so for a 14 diplomatic reputation Austria: if any Austrian PU subject has 70+ provinces, forget an inheritance even at 14 dip rep, barring stability and culture group influence.


The inheritance chance of random nations is calculated the same as above, but is ALSO dependant on them being in the right tier (see chapter 4) -which is EXTREMELY RARE- and on another rule: you can only inherit a nation if you have twice their province number, and IF the nation is smaller then 15 provinces.


IF IR<IT you will inherit nation on step C. It should be noted if multiple PUs have same IT they will be all inherited simultaneously or not at all.

C) Inheritance itself, happens when new ruler takes throne for PUs and when their ruler dies for DS. For PUs if check didn't pass they will stay your PU (assuming positive relations). For DS nations will either be inherited, become your PU, cause succession war or gain your dynasty, depending on the tier they are in. Vassals will never become personal unions, but can be inherited (including, in extreme cases, vassals of other nations o_O).

Only Inheritance threshold can be influenced without use of console.


2. EXAMPLE, because examples are easier to understand:

let us take Burgundy as example, led by a player, past 1500.

All three PU subjects of Burgundy can be inherited. Burgundy also has a chance to 1. to inherit the OPM independent heirless nation of Lorraine , and 2. to inherit their heirless vassal Nevers because both of those nations are in the right TIER to be inherited.

------> Step A:

Burgundy king took the throne decades ago, and the inheritance roll occured that day with a 100 sided dice, d100. The game rolled 10.

------> Step B:

1. Burgundy has three PU subjects. The king in Burgundy dies, or abdicates. The game compares the IR inheritance roll in step a versus the IT inheritance threshold chance of Burgundy' PU subjects (the chances can vary depending on current diplo reputation and stability, see formulae above). The IR inheritance roll is BELOW the IT inheritance threshold chance for all three subjects (meaning that IR 10 was lower then the xx%chance to inherit), which leads to inheritance of all three in step C. If the inheritance threshold roll is only lower then the inheritance chance for only ONE of the PU subjects, then Burgundy will only inherit that PU subject. Or two outta three. Or none.

2. Nevers and Lorraine have an invisible high inheritance threshold chance because they only have a few provinces. Since Nevers is a vassal of Burgundy and cause Lorraine is independent, the check for inheritance happens when *their* ruler dies. The new King of Burgundy was in line to inherit Nevers and Lorraine IF their ruler ever dies heirless while those nations are in the inheritance tier, because the inheritance roll of Burgundy was the lowest of all the possible successors with inheritance chance.

So, if a nation gets really Lucky to be strongest successor while random nation is in inheritance tier and their ruler dies heirless.. You can then inherit nations half your province number with a maximum province number of 15..

example: A player once reported seeing Muscovy inherit entire Denmark, without them sharing dynasty (with just RM done). Muscovy must have had REALLY low inheritance roll to go under the very small inherit threshold chance to inherit Denmark. The default outcome would have been that Muscovy delivers noble to take throne in Denmark.

Are you still with me ;)

Note AGAIN that the inheritance threshold chance to inherit independent nations will be a LOT higher if you stack a load of diplomatic reputation. A 14 dip reputation Austria can inherit eglible random nations easily depending if their ruler dies heirless in in the right tier, or if their PU subjects have lower province number then Austria diplo reputation x 5.



------> Step C:

Burgundy gets cores on ALL the provinces of the nations that get inherited, and all nations inherited by Burgundy vanish from the map, becoming territory of Burgundy. Having negative opinion with legible inheritance subjects WILL prevent the inheritance, and might lead to the normal 'break union'. What happens to vassals/colonial nations of inherited nations needs to be tested still.

3. Important tips:

*if you see in diplomatic window of PU subjects that you will inherit one or even 5 at once, then ABDICATE. You will inherit them all immediatly, if it showed you would.


*for best chances of inheritance you should maximize your diplomatic reputation (and stability for that little extra nudge) when your ruler gets old (40 age or 50 age should be good threshold to do it, depending whether your ruler is general or not), additionally you can use enforce culture (if available) to gain an extra 5% chance.

Can you see now WHY Austria inherits a lot? They got high natural diplomatic reputation as emperor, their stability is usually high, and their culture group consists MANY nations.

*Keep these parameters as high as possible until they are no longer in DS. When trying to inherit nations in DS it is advisable to focus on nations within your own culture group, and to weight benefits of inheritance with risk of gaining them as PU instead.
 
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Hi, thanks for all the great info on this complicated topic. I feel there's one piece of info missing though:

For T0 the case in which the target nation has RM AND a dynasty isn't specified.

What happens in that case? The same as when there is a dynasty and no RM (which would be instant PU or SW).

Thank you!

Tier 0 (the default case):

a) no RM & no dynasty: local noble succeeds

b) RM & no dynasty:
- strongest RM member spreads her dynasty

c) No RM & dynasty:
- no valid Contestants exist: PU
- valid Contestant exists -> SW between Successor and Contestant) RM & dynasty:
- if other dynasty members are too weak -> strongest RM member spreads her own dynasty (i.e. Ryazan can't contest a dynasty spread from Austria over Muscovy)
- if at least 1 dynasty member is strong enough to block the spread -> SW between Successor and Contestant.
 
Interesting guide, this has taught me a lot on how I get a PU. Annoying as most of it is luck though.

I actually got my first diplo-union after 400 hours of trying with minimal luck - it was a union over a catholic Savoy as protestant Burgundy in a multiplayer game - although I had to fight two re-unification wars because negative opinion breaks the union (the first war was caused by this) - and my ruler's well-timed decision to die after two years of ruling Burgundy with the war literally ending a month before he died meant I had to fight for the union after a 13 years' truce (again. At 44 years of age. Yes it was really bad luck). The upside is I got a de Trastamara on my throne because the other player was on Spain (my friend), so I can dynasty blob :D
 
I apologize if I missed that in the guide, but could you add also some tips & tricks for how to handle junior PU partners once you have them? Specifically, how best to integrate or inherit? Thx!
 
I apologize if I missed that in the guide, but could you add also some tips & tricks for how to handle junior PU partners once you have them? Specifically, how best to integrate or inherit? Thx!

PU subjects are best subjects you can have. They will field biggest armies, have best economy, and lowest liberty desire for their development.

so you can feed them their entire culture group, and still not see the need to integrate them, providing you grow in EQUAL size. At least feed PU subjects up to their state limit.

staying at war constantly prevents them from declaring independence. Keep a rival slot if you got a rebellious PU subject, and rival whoever is supporting the independence of the PU subject. Then just declare on your new rival with humiliate CB to make PU subject lose independence support.

I'd only integrate PU subjects in age of absolutism on 100% absolutism, and ONLY the ones that you cannot inherit naturally. So, the tiny ones should never be integrated. The only reason to integrate PU subjects earlier, is TRADE. For example.. if you play Savoy and you got Milan in a PU early on.. Then it might be better to integrate Milan ASAP to stop them from leeching trade income away.

regarding inheritance: The full probability to inherit -for PU overlord or strongest successor for inheritance tier heirless (vassal) nations- can be calculated as 5 x Diplomatic Reputation for + Stability (Senior) + 5 if both partners share a culture group -1 per province in the junior partner or inheritance tier heirless nation.

I bet you say "wait what" now :rolleyes:

The rule of thumb is you can start to get % chance to inherit a junior PU or random nation that has dip rep times 5 in amount of provinces. You will get chance even sooner if you share culture, and a bit more if you got +3 stab.

important sidenote: Take into account that stacking these modifiers doesn't mean a guaranteed inheritance; the roll the game does on monarch taking throne has to be good enough. The modifers above just widen the range in which the inheritance roll is successful (which is something that is not very Obvious).

example: Austria has 10 diplo rep, 3 stability. Same culture group 3 province nation is heirless and in inheritance tier and their ruler dies , or Austria 3 province PU subject has been subject for 50+ years and new ruler takes throne in Austria.
Austria would get 50% chance from dip rep, 3% from stability, 5% from same culture group and -3% from 3 provinces in PU/DS for a total of 55% as inheritance treshold chance.

the inheritance chance of PU subject is calculated with diplomatic Reputation, which is 5% per point, and number of provinces owned by the junior, which is -1% per province. Austria would get 70% chance to inherit at 14 dip rep, before counting provinces of junior PU or DS.

so for a 14 diplomatic reputation Austria: if any Austrian PU subject has 70+ provinces, forget an inheritance even at 14 dip rep, barring stability and culture group influence.


Hope this helps. If not, you are going to have to ask more specific questions :)
 
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Edit: this comment doesn't apply anymore, because it was a reply to a comment which has since been corrected.
To inherit naturally, it is important to grow constantly. In the formulae, your amount of provinces matters a lot. Also diplomatic reputation. So if you run a PU heavy Spain/Austria/England campaign (thanks to their mission tree) it can pay off to take diplomatic and influence ideas, and pair it with any idea group that gives diplomatic reputation bonus from policies. In THEORY a big Austria can inherit a full fledged Siberia colonized Russia that way.
In what way does growing have any impact on inheriting a junior partner? Doesn't the formula just depend on dip rep, stability, culture and the number of provinces of the junior partner? Or is the wiki wrong about this?
 
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In what way does growing have any impact on inheriting a junior partner? Doesn't the formula just depend on dip rep, stability, culture and the number of provinces of the junior partner? Or is the wiki wrong about this?

I derped out, need more coffee. Mixed the chance of getting union with inheritance haha. so nevermind... Please delete your comment ;)

edited previous post with the real formulae.
 
Yep. that helps! with explanation, at least ...

Though in my case, playing Byzantium (not Austria), so the max DIP REP I can dream of is in the range of 7-8 points, if I become emperor after religious peace, and without any policies. In comparison, size of country modifier for Castile is 29%, and for France 35%.

Originally, I wanted to form Roman Empire before the age of absolutism, which seems out of reach because absorbing all PUs will still take ~ 100 years or so.That is why I am looking for some magic to happen ...

Here is the specific question left: if rules does not die but abdicate, does that still trigger the PU inheritance mechanics?
 
Yep. that helps! with explanation, at least ...

Though in my case, playing Byzantium (not Austria), so the max DIP REP I can dream of is in the range of 7-8 points, if I become emperor after religious peace, and without any policies. In comparison, size of country modifier for Castile is 29%, and for France 35%.



Here is the specific question left: if rules does not die but abdicate, does that still trigger the PU inheritance mechanics?

Yes. Any new ruler triggers it.
 
Yes. Any new ruler triggers it.

Actually, I doubt it. As Byzantium, I have France, Castile and Burgundy as junior PUs, with inheritance chance of 8%, 14% and 16%. Now that I maximized diprep, I tried to simulate and abdicated my ruler for ~ 20 times in a row. Not a single instance of inheritance happened.
 
Actually, I doubt it. As Byzantium, I have France, Castile and Burgundy as junior PUs, with inheritance chance of 8%, 14% and 16%. Now that I maximized diprep, I tried to simulate and abdicated my ruler for ~ 20 times in a row. Not a single instance of inheritance happened.

That is normal .. the roll to inherit happens when ruler takes the throne. Not when he dies

Meaning that crashing client even 100 times will always still have same result, cause the roll happend decades before.
 
That is normal .. the roll to inherit happens when ruler takes the throne. Not when he dies

Meaning that crashing client even 100 times will always still have same result, cause the roll happend decades before.

so in theory having a 200 yr old ruler and 200 yr old heir and 100 prestige it should be possible to save/reload until you get them?
 
Its all irrelevant.

Only getting lot of dead kings to means more chances to roll a good roll to inherit.. when the nex king takes throne.

This is why elective monarchy is good to play PU game.

Due to constant old monarchs.. you get more chances to inherit.

In theory you could flip republic until you inherit.. then go monarchy again... get PU.. rinse repeat
 
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so in theory having a 200 yr old ruler and 200 yr old heir and 100 prestige it should be possible to save/reload until you get them?

No, saving and re-loading will never change the die roll behind the inheritance check. The only way to get a different result would be to reload and increase stab/dip rep and even that will only work if the original roll is close enough to what is required. The age is irrelevant, the prestige is irrelevant; all that matters is dip rep, stability, culture, the number of provinces owned by the junior, and the die roll made when the previous ruler was crowned.
 
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There is a lot to be said for taking Diplomatic Ideas and just being vigilant. Check that shopping list of heirless countries frequently. Just mucking around with a France game now (before France gets massively changed next patch) and I noticed Hungary had a 50ish year old ruler and no heir. This is a pretty successful Hungary, untouched by the Green Menace and not subsumed into Austria. I chuck an RM into them - literally two days later a message pops up to tell me we have formed a union with Hungary. Brilliant. And what's more they have Lika (coastal province) so I have easy access to the country. It's a strategically very valuable spot - right on the doorstop of both Austria and the Ottomans and limits the expansion opportunities for both as well. What a lovely gift from RNGesus.
 
No, saving and re-loading will never change the die roll behind the inheritance check. The only way to get a different result would be to reload and increase stab/dip rep and even that will only work if the original roll is close enough to what is required. The age is irrelevant, the prestige is irrelevant; all that matters is dip rep, stability, culture, the number of provinces owned by the junior, and the die roll made when the previous ruler was crowned.

right but that's why I'm saying an old heir and old ruler and reloading every time to see the ruler die and then the heir die right after taking the throne, it's decided when the heir takes the throne and he'll take it nearly instantly in this case as both are 200, or maybe make the heir only 100 so he dies a little slower, it's a thought experiment after all
 
atwix said:
Are you implying by this that getting restoration of union cb on a RM partner that uses "introduce heir" is working as designed?

I thought this was buggy.
Darth. said:
Assign heir? Do you mean "Introduce Heir"? How does that give a PU cb?
Introduce Heir was referred to as Assign Heir internally, hence the different phrasing, but yes the intention is if you use it any nation that has a royal marriage with you will obtain a Restoration of the Union CB against you (provided you meet the other requirements for being in a Personal Union).




so this means getting restoration of union cb on ANY RM partner that uses "introduce heir" option is working as designed o_O
 
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I have never seen this happen, and could use some feedback on how this triggers. The war of the roses ended and Portugal installed their dynasty on the english throne, and let Lancaster and York bicker on. Can this happen if you support your RM partner in the disaster?
 
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The original claimant chosen died without an heir and, per usual, the largest nation with a RM got installed then eventually ended the disaster. I've seen that sort of thing happen a few times over the years but it's not common.